This invention relates to a releasable lock for an excavating tooth and, more particularly, to a lock wherein the pin and plug have unique confronting, interengaging faces.
This invention is an improvement on co-owned U.S. Pat. No. 3,126,654 which in turn constituted an improvement over co-owned U.S. Pat. No. 2,919,506.
As was brought out in the above-mentioned U.S. Pat. No. 3,126,654 patent, locking devices for excavating teeth have had to resolve two conflicting objectives, i.e., providing a secure lock to withstand severe shocks encountered during earth working yet be readily disassemleable for the replacement of the wearable point. In large measure this has been achieved by the "corrugated" lock of the above-mentioned patents. However, in certain severe environments, the corrugated locks have not performed their intended function. Severe shock or impact blows have, on occasion, caused the pins literally to be "squirted" out of their engagement with the mating plug -- thereby bringing about a situation frequently encountered in the prior art and which normally was solved by deforming an end portion of the pin. This, of course, resulted in greater security of installation but frustrated the achievement of quick replaceability. It will be appreciated that where the work is so severe as to disassemble the lock, as mentioned above, the equipment used therefor is usually of a rugged and expensive nature so that the additional downtime required for burning, chipping, chiseling or otherwise removing the locking pin, is quite expensive. On the other hand, if the lock is not absolutely secure, loss of the removably mounted point can result in serious damage to the adapter and again valuable time is lost in the replacement.
This dilemma has been resolved according to the invention which employs unique angularly related substantially rigid planar surfaces forming alternating crests and valleys on both the pin element and the plug element. When lock elements according to the invention are employed in the above-described severe operating conditions, the previous experience of lock loss has been remedied. The provision of such an advantageous locking device constitutes an important object of the invention. Other objects and advantages of the invention may be seen in the details of the ensuing specification.